The phylogeny of a reduced ‘sand goby’ group based on behavioural and life history characters

Phylogenetic analysis of 27 behavioural and life history traits for five Mediterranean sand goby species (Perciformes, Gobiidae) produced one tree with a consistency index (excluding uninformative characters) of 0.756. This tree agreed with previous molecular analyses in providing strong support for the monophyly of the sand gobies, indicating that Pomatoschistus and Knipowitschia are paraphyletic and helping to resolve the ambiguous position of Economidichthys pygmaeus, placing it as the basal member of the reduced data set. Although the tree was completely resolved, the branches above E. pygmaeus were only moderately supported in the bootstrap analysis. Overall, the behavioural data provide information that may eventually help clarify the speciation bursts within the Mediterranean sand goby clade as much as is possible. © 2012 The Linnean Society of London, Zoological Journal of the Linnean Society, 2012, 165 , 916–924.     

Intensified organic carbon dynamics in the ground water of a restored riparian zone

1. River restoration projects usually aim at improving the physical habitat for aquatic organisms. The extent to which biogeochemical processes and microbial activities are intensified in restored river reaches remains uncertain. 2. Here, we investigated the relationships between the distribution and composition of organic carbon (OC), bacterial secondary carbon production and extracellular enzymatic activity (EEA) in the ground water below a restored riparian section of the River Thur, Switzerland, relative to a channelised section. The spatiotemporal variability in the stable C isotopic ratio, dissolved OC polydispersity (the distribution of molecular mass in a mixture of molecules) as well as bacterial abundance, EEA and secondary production were investigated in different process zones. 3. At high river discharge, humic as well as low molecular weight amphiphilic substances infiltrated into the subsurface in a zone dominated by the pioneer plants Salix viminalis (willow bush). Concurrently, bacterial abundance, EEA and secondary carbon production increased at this location. 4. The willow plants leached bioavailable substrates into the ground water when the water table was high. The flood‐driven soil–groundwater coupling stimulated EEA and bacterial secondary production of the suspended groundwater bacterial community. 5. Establishing riparian habitat diversity adds hot spots of OC inputs during flood events, potentially providing valuable ecosystem services (e.g. degradation of organic pollutants) that accompany.     

Variation in aggressiveness in house mouse populations

Clearly the ability of 'house mice' to vary their social structures is an important feature contributing to their success in a wide range of habitats. Social structure is strongly influenced by aggressiveness and other behaviours in male and female mice. Material is presented illustrating how genotype, intrauterine location and social experiences influence dyadic encounters in this 'species'.     

Critical Social Learning: A Solution to Rogers's Paradox of Nonadaptive Culture

Alan Rogers (1988) presented a game theory model of the evolution of social learning, yielding the paradoxical conclusion that social learning does not increase the fitness of a population. We expand on this model, allowing for imperfections in individual and social learning as well as incorporating a "critical social learning" strategy that tries to solve an adaptive problem first by social learning, and then by individual learning if socially acquired behavior proves unsatisfactory. This strategy always proves superior to pure social learning and typically has higher fitness than pure individual learning, providing a solution to Rogers's paradox of nonadaptive culture. Critical social learning is an evolutionarily stable strategy (ESS) unless cultural transmission is highly unfaithful, the environment is highly variable, or social learning is much more costly than individual learning. We compare the model to empirical data on social learning and on spatial variation in primate cultures and list three requirements for adaptive culture.     

Evidence of alarm pheromones in the venom of Polistes dominulus workers (Hymenoptera: Vespidae)

Abstract.  The active and coordinating capacity of defending the nest is a key feature of social insects. The present study investigates the presence of alarm pheromones in the venom of workers of the social wasp, Polistes dominulus . Laboratory experiments were performed with caged colonies of P. dominulus using a wind tunnel apparatus to test the behavioural response of workers to venom released by other workers and to venom extracts. Contrary to that previously reported for European paper wasps, the present results show that the venom is the source of alarm pheromones. Field experiments combining a visual (black target) and a chemical stimulus (venom extract) were performed to test the effect of the venom on the reaction of colonies. Wasps leave the nest, land on the visual target and attack the target significantly more once exposed to venom extract plus target than to solvent plus target. This work shows that the venom of P. dominulus workers elicits an alarm response, reduces the threshold for attack and acts as an attractant on targets. These results using P. dominulus indicate that, in both American and European species, colony defence is based on the same features, suggesting that chemical alarm is a widespread trait in the genus Polistes .